Component Damage

On Tue, 13 Jun 2017 20:21:10 -0000 (UTC), Cursitor Doom
<curd@notformail.com> wrote:

Has anyone ever caused damage to static-sensitive components through the
use of compressed air? Is this something we really need to be mindful of?
Click to expand...

I worked in a factory once that did a lot of cleaning of electronic
modules. Air was supplied by a central compressor. I never had a
problem with static and I don't think anyone else did but how would we
have known as many of the modules were already faulty.

Steve

--
Neural Network Software for Windows http://www.npsnn.com
 
On Tue, 13 Jun 2017 14:38:44 -0700 (PDT), tabbypurr@gmail.com wrote:

On Tuesday, 13 June 2017 22:03:32 UTC+1, Cursitor Doom wrote:
On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?

Haha! I think even those old germanium diodes would easily cope with a
four foot fall!

I think those would be some of the more fragile items. Many have an extremely thin filament stretching a few mm with no support at all.


NT
Click to expand...

Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs (among other things) http://www.viatrack.ca

void _-void-_ in the obvious place



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On 13/06/2017 21:21, Cursitor Doom wrote:
One of the books I picked up on faultfinding and troubleshooting whilst
in London the other day (title escapes me but I can find it if anyone
cares) states that:

a) A bipolar transitor may be permanently damaged by dropping it on a
concrete floor from a height of over 4'. (I'm paraphrasing but that's the
gist of it).

Elsewhere it states that:

b) static sensitive components can be damaged by careless use of air
dusters, which can build up a static charge, in their vicinity.

Whilst I'm prepared to place some faith in assertion b) I'm reluctant to
do so in the case of a). However, I'm more concerned with b) because I
recently purchased a fair sized air compressor for blowing dust out of
the insides of test equipment which is of course considerably more
powerful than the aerosol cans the author was thinking about when he
asserted b).
Has anyone ever caused damage to static-sensitive components through the
use of compressed air? Is this something we really need to be mindful of?
Click to expand...

I've used a 1KW handheld Martindale blower for decades, no known static
problem ,just occassional physical breakage of shielding or something
like that, because of the air pressure involved, blowing out
tarry/greasy/hairy crud.
 
"Cursitor Doom" <curd@notformail.com> wrote in message
news:eek:hpjo9$ckb$2@dont-email.me...
On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?


NT

Haha! I think even those old germanium diodes would easily cope with a
four foot fall!
Click to expand...

diodes would be OK but die mounting and bond wires in some germanium
transistors was well, err - a bit amateurish.

Nowadays; suppliers pack *ANY* components in anti-static bags - it used to
be some sort of clue which bits to handle with care.

There's some unexpected parts on the vulnerable list, so maybe they have a
point.

molded semiconductors can be subjected to pretty much anything that doesn't
break the case.
 
<tabbypurr@gmail.com> wrote in message
news:253e500a-c0b0-43d3-8ffd-c8de9add639f@googlegroups.com...
On Tuesday, 13 June 2017 22:03:32 UTC+1, Cursitor Doom wrote:
On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?

Haha! I think even those old germanium diodes would easily cope with a
four foot fall!

I think those would be some of the more fragile items. Many have an
extremely thin filament stretching a few mm with no support at all.
Click to expand...

The first successful anti aircraft shell proximity fuze that could be fired
out of a gun had 3 hearing aid style tubes.

The thyratron obviously isn't a hearing aid tube - its about the sixe &
shape of the glass envelope.
 
"whit3rd" <whit3rd@gmail.com> wrote in message
news:1b44ec1e-c2cc-432c-946c-e7be3b97c839@googlegroups.com...
On Tuesday, June 13, 2017 at 2:03:32 PM UTC-7, Cursitor Doom wrote:
On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?

Haha! I think even those old germanium diodes would easily cope with a
four foot fall!

Oh, no; a point contact diode can easily jar out of spec. There was even
an old device (the 'coherer') which reformed a rectifying contact by
motorized shaking during normal operation.
Click to expand...

AFAIK: the point is "burned in" during manufacture. The weld is pretty much
the alloying process that creates the PN junction.

They're much less fragile than the old catswhisker/galena crystal.
 
<oldschool@tubes.com> wrote in message
news:qha1kcpqi8052hbeug8v41fn4ki2lnqlk3@4ax.com...
On Tue, 13 Jun 2017 20:59:53 -0000 (UTC), Cursitor Doom
curd@notformail.com> wrote:

On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?


NT

Haha! I think even those old germanium diodes would easily cope with a
four foot fall!

Dont try that with a vaccuum tube!
Click to expand...

I've seen one or two bounce - not very often though.
 
"mike" <ham789@netzero.net> wrote in message
news:eek:hq53p$cd1$1@dont-email.me...
On 6/13/2017 5:02 PM, Trevor Wilson wrote:
On 14/06/2017 9:43 AM, Dave Platt wrote:
In article <eqb9r2F4pmkU1@mid.individual.net>,
Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> wrote:

The one caveat I would add about blasting boards with (clean)
compressed
air is that you *gotta* do it outdoors for all sorts of reasons I
can't
be assed to go into here.

**And yet another good reason to use a vac.

In particular: I'd be cautious about using compressed air to clean out
electronic equipment that's been stored in sheds, barns, or other
locations where there might be rodent activity. I've seen some pretty
grotty equipment donated to our ham club, which I thought might well
have been peed or pooped upon by rats and/or mice.

Hantavirus is no joke.

**I confess that I had not thought of that, but certainly, spreading any
dust around can be injurious to many people.


A vacuum, particularly one with a HEPA filter, would be safer than
compressed air (either indoors or outdoors).

**Of course. And MUCH safer for the equipment.


How do you get the cat hair out of the CPU heat sink underneath the fan?
Click to expand...

Its very easy when you don't have a cat - but since you do, odour killing
cat litter is great for packing in gear that came from a heavy smoker
household.
 
"Trevor Wilson" <trevor@SPAMBLOCKrageaudio.com.au> wrote in message
news:eqbtpdF8peuU1@mid.individual.net...
On 14/06/2017 11:58 AM, mike wrote:
On 6/13/2017 5:02 PM, Trevor Wilson wrote:
On 14/06/2017 9:43 AM, Dave Platt wrote:
In article <eqb9r2F4pmkU1@mid.individual.net>,
Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> wrote:

The one caveat I would add about blasting boards with (clean)
compressed
air is that you *gotta* do it outdoors for all sorts of reasons I
can't
be assed to go into here.

**And yet another good reason to use a vac.

In particular: I'd be cautious about using compressed air to clean out
electronic equipment that's been stored in sheds, barns, or other
locations where there might be rodent activity. I've seen some pretty
grotty equipment donated to our ham club, which I thought might well
have been peed or pooped upon by rats and/or mice.

Hantavirus is no joke.

**I confess that I had not thought of that, but certainly, spreading any
dust around can be injurious to many people.


A vacuum, particularly one with a HEPA filter, would be safer than
compressed air (either indoors or outdoors).

**Of course. And MUCH safer for the equipment.


How do you get the cat hair out of the CPU heat sink underneath the fan?

**I vacuum it out, possibly with the aid of a brush.
Click to expand...

Since de fluxing solvents were banned to protect the ozone layer, most
electronics is cleaned with water - sometimes its an option, sometimes it
isn't.

Dish wash detergent works great, but they thicken it with salt - so make
sure you rinse it all out.
 
<oldschool@tubes.com> wrote in message
news:kb91kcpo10v816r7c1h51h8n3p9p3l7v2q@4ax.com...
On Tue, 13 Jun 2017 16:43:38 -0700, dplatt@coop.radagast.org (Dave
Platt) wrote:

In article <eqb9r2F4pmkU1@mid.individual.net>,
Trevor Wilson <trevor@SPAMBLOCKrageaudio.com.au> wrote:

The one caveat I would add about blasting boards with (clean)
compressed
air is that you *gotta* do it outdoors for all sorts of reasons I can't
be assed to go into here.

**And yet another good reason to use a vac.

In particular: I'd be cautious about using compressed air to clean out
electronic equipment that's been stored in sheds, barns, or other
locations where there might be rodent activity. I've seen some pretty
grotty equipment donated to our ham club, which I thought might well
have been peed or pooped upon by rats and/or mice.

Hantavirus is no joke.

A vacuum, particularly one with a HEPA filter, would be safer than
compressed air (either indoors or outdoors).


I have not had rodents in my equipment,
Click to expand...

A few years back I Freegled an old RF signal generator with a dead spider
wedged behind the frequency dial.

I'd done repairs and cleaning, it had a bodged voltage regulator and I never
got the AF modulator going - I just couldn't be bothered taking out the
whole chassis to get at the spider.
 
"Dave Platt" <dplatt@coop.radagast.org> wrote in message
news:9a961e-hsl.ln1@coop.radagast.org...
In article <frCdnbCAQueXy93EnZ2dnUU7-XvNnZ2d@giganews.com>,
Jon Elson <jmelson@wustl.edu> wrote:

I have seen a fat spark produced when firing off a CO2 fire extinguisher,
which seemed like a pretty big design defect.
Click to expand...

The one I fished out of a skip is now fitted with a tyre adaptor and used
for blowing tubeless tyre onto the rim.

You have to hold it upside down - if the syphon tube puts liquid CO2 into
the tyre, the rim starts creaking ominously.
 
"Stephen Wolstenholme" <steve@easynn.com> wrote in message
news:25v1kc1vcie0ncakqj8garf1u86lon9qst@4ax.com...
On Tue, 13 Jun 2017 20:21:10 -0000 (UTC), Cursitor Doom
curd@notformail.com> wrote:

Has anyone ever caused damage to static-sensitive components through the
use of compressed air? Is this something we really need to be mindful of?

I worked in a factory once that did a lot of cleaning of electronic
modules. Air was supplied by a central compressor. I never had a
problem with static
Click to expand...

At tea break a bunch of us sat on the compressor - somehow I always ended up
next to the intake filter, and I tend to fart.
 
On Fri, 16 Jun 2017 21:48:37 +0100, Ian Field wrote:

molded semiconductors can be subjected to pretty much anything that
doesn't break the case.
Click to expand...

Are you the same Ian Field that has authored several books on UHF/VHF
subjects?
 
On Sunday, June 18, 2017 at 11:44:48 AM UTC-4, Cursitor Doom wrote:
On Fri, 16 Jun 2017 21:48:37 +0100, Ian Field wrote:

molded semiconductors can be subjected to pretty much anything that
doesn't break the case.

Are you the same Ian Field that has authored several books on UHF/VHF
subjects?
Click to expand...

Plasma physics too...

oh sorry that was Ion Fields. :^)

George H.
 
On 2017/06/16 1:48 PM, Ian Field wrote:
"Cursitor Doom" <curd@notformail.com> wrote in message
news:eek:hpjo9$ckb$2@dont-email.me...
On Tue, 13 Jun 2017 13:45:40 -0700, tabbypurr wrote:

I'd first be mindful of mechanical damage from doing that. When was the
book written? Germanium?


NT

Haha! I think even those old germanium diodes would easily cope with a
four foot fall!

diodes would be OK but die mounting and bond wires in some germanium
transistors was well, err - a bit amateurish.

Nowadays; suppliers pack *ANY* components in anti-static bags - it used
to be some sort of clue which bits to handle with care.

There's some unexpected parts on the vulnerable list, so maybe they have
a point.

molded semiconductors can be subjected to pretty much anything that
doesn't break the case.
Click to expand...

IC sockets though? Why do they pack them in anti-static bags (Digi-Key)!

John ;-#)#
 
On 6/19/2017 3:43 PM, John Robertson wrote:
IC sockets though? Why do they pack them in anti-static bags (Digi-Key)!

John ;-#)#
Click to expand...

For the same reason drive through ATMs have instructions in Braille.

One kind of something is cheaper to inventory than two kinds of
something.

If you don't inventory non-static bags, nobody gets sensitive parts
in the wrong bags.


--
Jeff-1.0
wa6fwi
http://www.foxsmercantile.com

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On 2017/06/19 2:07 PM, Foxs Mercantile wrote:
On 6/19/2017 3:43 PM, John Robertson wrote:
IC sockets though? Why do they pack them in anti-static bags (Digi-Key)!

John ;-#)#

For the same reason drive through ATMs have instructions in Braille.

One kind of something is cheaper to inventory than two kinds of
something.

If you don't inventory non-static bags, nobody gets sensitive parts
in the wrong bags.
Click to expand...

Now that makes sense. I imagine that the cost of anti-static vs regular
bags is minuscule when you buy at Digi-Keys volume.

Thanks,

John :-#)#
 
On 19.06.2017 22:43, John Robertson wrote:
On 2017/06/16 1:48 PM, Ian Field wrote:

Nowadays; suppliers pack *ANY* components in anti-static bags - it
used to be some sort of clue which bits to handle with care.

There's some unexpected parts on the vulnerable list, so maybe they
have a point.

molded semiconductors can be subjected to pretty much anything that
doesn't break the case.

IC sockets though? Why do they pack them in anti-static bags
(Digi-Key)!
Click to expand...

Most likely for compliance reasons. Thanks to the general CYA style
over-protectiveness, ESD safety rules are going postal. In various
places, rather than using common sense and somewhat educated employees,
they don't allow any sort of non-ESD-protected items on the production
floors any more. Having the sockets delivered in a non-dissipative
plastic bag would have some QC lunatics throw a hissy fit and run
screaming because they found something (the bag) that was (allegedly)
compromising the ESD safety of the factory :)
 
On Mon, 19 Jun 2017 16:07:31 -0500, Foxs Mercantile <jdangus@att.net>
wrote:

>For the same reason drive through ATMs have instructions in Braille.

Not really. Drive-up ATMs have Braille because it is not uncommon for
a blind person to take a cab or have a friend drive them to the bank
and use the ATM from the back seat or get out and walk to the drive-up
ATM while their friend monitors them for safety. The National
Federation of the Blind insisted that ALL ATMs provide a means for use
by blind people.
 
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